There are currently no suitable arrangements for adjustment of robot arms in order to be able, through exact measurement of the angular relationship in one or several of the joints of the robot arm, to make an exact adjustment of the outer end of the robot arm, that is, its working point. It has instead been necessary to depend on being able to control the gear or other driving system that achieves turning of the joint, based on a defined initial condition, such that the working point adopts the desired position. There is no possibility of verifying the setting at a particular joint.